Strict Standards: Redefining already defined constructor for class wpdb in /home/carterfd/public_html/blog/wp-includes/wp-db.php on line 52

Deprecated: Assigning the return value of new by reference is deprecated in /home/carterfd/public_html/blog/wp-includes/cache.php on line 36

Strict Standards: Redefining already defined constructor for class WP_Object_Cache in /home/carterfd/public_html/blog/wp-includes/cache.php on line 389

Strict Standards: Declaration of Walker_Page::start_lvl() should be compatible with Walker::start_lvl($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 537

Strict Standards: Declaration of Walker_Page::end_lvl() should be compatible with Walker::end_lvl($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 537

Strict Standards: Declaration of Walker_Page::start_el() should be compatible with Walker::start_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 537

Strict Standards: Declaration of Walker_Page::end_el() should be compatible with Walker::end_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 537

Strict Standards: Declaration of Walker_PageDropdown::start_el() should be compatible with Walker::start_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 556

Strict Standards: Declaration of Walker_Category::start_lvl() should be compatible with Walker::start_lvl($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 653

Strict Standards: Declaration of Walker_Category::end_lvl() should be compatible with Walker::end_lvl($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 653

Strict Standards: Declaration of Walker_Category::start_el() should be compatible with Walker::start_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 653

Strict Standards: Declaration of Walker_Category::end_el() should be compatible with Walker::end_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 653

Strict Standards: Declaration of Walker_CategoryDropdown::start_el() should be compatible with Walker::start_el($output) in /home/carterfd/public_html/blog/wp-includes/classes.php on line 678

Deprecated: Assigning the return value of new by reference is deprecated in /home/carterfd/public_html/blog/wp-includes/query.php on line 21

Deprecated: Assigning the return value of new by reference is deprecated in /home/carterfd/public_html/blog/wp-includes/theme.php on line 508
hacked by cyber_hunter » Blog Archive » Family Day at MIT’s Lincoln Lab

Family Day at MIT’s Lincoln Lab


Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /home/carterfd/public_html/blog/wp-includes/formatting.php on line 74

Yesterday Lincoln Lab had an open house for family members of current and former employees on its main campus in Lexington, MA. My grandfather worked there for many years until he retired a decade ago, so he extended the invitation to my dad and I. It took the form of a science fair, with each research group (or a fair number of them, at least) doing a demonstration of whatever it was they were working on. We only visited some of them - there were too many see all of them. I’m afraid they didn’t allow photography, as a lot of research there is done for the government (and is thus classified).

The first exhibit we saw was on thermo-electric systems that can convert electricity to heat or vice-versa. Interesting technology, but not very efficient.

Next there was a display on lasers. One part had a 532 nm green laser shining through a fiber optic cable. Some of the light was absorbed by the fiber and re-emitted at different wavelengths, so that when the beam was sent through a prism it split into a rainbow covering the visible spectrum and a bit on either side of that. Another display at the same table had a red laser (probably 650 nm) shining through a tank of water. Directly opposite the laser was a hole that allowed a stream of water to pour out in an arc that hit a mirror a few centimeters below the level of the laser. The laser beam was carried by the water stream to hit the mirror.

Next was a display on high-speed imaging. They have a CCD sensor capable of taking a million images per second (IIRC), although it’s only used for bursts of a few dozen images.

Next was a display on microchips, which had several microscopes focused on silicon wafers. Always cool to look at those. There were also several tables discussing the fabrication process. One had some blank wafers and a vacuum wand for picking them up.

We then walked through several buildings until we found the scanning electron microscope demo. One was in operation for the demo, so we got to see highly magnified views of a CCD sensor (which looks like the canework on some chairs), a bee, tiny sea creatures, blood cells, and a kind of pollen. The latter was amusing to watch because the electron beam was charging up the pollen particles, which then repelled one another.

From there we headed over to the machine shop. First we saw the rapid-prototyping machine, used to make plastic parts for various things. Sometimes the parts are used as-is, other times they are prototypes for something to be made in a different material. Next we saw a computer-driven milling machine which was making Family Day souvenirs out of aluminum billets. Finally we saw the abrasive water jet cutting machine. As the name suggests, it cuts through materials with a water jet. It can cut through up to 8 inches of solid metal.

Next we saw the room where they assemble circuit boards. Nothing was running at the time, but we could examine the machines used to put solder paste on blank circuit boards (a screen is placed over the board and fancy squeegee rolls over it, depositing the solder where it belongs), place resistors, diodes, and microchips on the board, and the oven used to melt the solder. (I/O connectors are added by hand later.)

We went to see another display that looked interesting, but as the presenter was off at lunch we decided to do the same. They had a pretty good buffet set up outside the main entrance (mmm, sirloin hamburgers )

After lunch we went back to the laser communications demo we had tried to see before lunch. Basically, the data (in this case, an audio stream from a mic) was sent by a laser to a receiver (which was connected to a speaker). Changing the amount of light reaching the receiver dramatically altered the volume of the speaker.

Then we visited the facility’s data center, which was the usual racks of servers and hard drives, providing several gigaflops of processing power and petabytes of RAID-5 data storage.

The library there has the TX-0 in its basement, which was one of the first transistor-based computers. It’s actually quite small - you could fit it into your living room. The design is interesting: many of the components are modular in nature, so a failed board could be replaced in a minute or two. The transistors are also interesting, as it appears they used the same connection interface as vacuum tubes. The main control panel had lights to indicate what was in the registers, quite convenient for debugging programs (back when you wrote everything in machine code). A very interesting machine to examine. Too bad it’s been inoperable for the last quarter-century.

Next we came across a demo of how radar works, using a sodar system (same concept as radar, but uses sound waves instead). A good round of applause is good for jamming sodar systems, BTW.

Finally, we went through a demo of 3D images and lasers. Wearing 3D glasses, we were able to watch a 3D computer model of Manhattan as an imaginary camera flew all over the city. Next to that was a giant multi-touch display table. Unlike the iPhone’s display, you have to wear a wristband connected to the display for it to properly work (the wristband completes a circuit that runs from the display and through your hand and lets it handle input from up to four people at once). Finally there was a big laser display that had the beam bouncing all over a table and then across the room. The latter part I disliked as the beam was at eye level. Although the beam had gone through a lens that dispersed it and made it harmless, this sets a poor example.

We had a wonderful time there. It’s a neat place.

Leave a Reply

You must be logged in to post a comment.